Typically, a substrate process system includes a plurality of arranged process machines. Circuit substrates are transported from an upstream process machine to a downstream process machine among the plurality of process machines. There is a substrate process system in which each process machine includes a pair of transportation devices, and circuit substrates are transported by the pair of transportation devices so as to improve productivity. That is, in this system, the circuit substrates are transported on two paths. A substrate process system disclosed in PTL 1 is an example of a system in which circuit substrates are transported on two paths.
PTL 1: JP-A-2011-134919